Shielded integrated circuit pad structure

Abstract

An integrated circuit pad structure includes a ground strip ( 206 ) positioned below a pad ( 101 ). In one example a conductive element ( 102 ) is coupled to the pad ( 101 ), and at least two tiled layers, positioned below the first conductive element ( 102 ) and positioned above the ground strip ( 206 ) are included. A conductor ( 203 ), may run beneath the ground strip ( 206 ). In a second example, a pad ( 101 ) is seated on a ground shield cage having a bottom conductive ground element ( 302 ) including several ground strips where at least one ground strip ( 116 ) is along a signal routing path. The ground shield cage further includes a set of stacked conductive ground elements, stacked to form sidewalls ( 209, 210 ) of the cage. The top conductive ground element ( 301 ) of the stacked elements has an inner perimeter and an outer perimeter, such that the inner perimeter surrounds the pad ( 101 ) and the top conductive ground element ( 301 ) is in the plane of the conductive element ( 102 ) coupled to the pad ( 101 ).

1. An integrated circuit comprising:
 a pad; 
 a ground strip element comprising a set of ground strips, positioned below said pad; 
 a first conductive element coupled to said pad; and 
 at least two tiled layers, positioned below said first conductive element and positioned above said ground strip element. 
 
     
     
       2. The integrated circuit of  claim 1 , further comprising:
 at least one conductor routed substantially beneath, and parallel to, a ground strip of said set of ground strips. 
 
     
     
       3. The integrated circuit of  claim 2 , wherein a ground strip width of said ground strip of said set of ground strips is at least equal to a conductor width of said at least one conductor. 
     
     
       4. The integrated circuit of  claim 1 , wherein said set of ground strips comprises three ground strips. 
     
     
       5. The integrated circuit of  claim 4 , wherein two of said three ground strips have an equal width and a third ground strip of said three ground strips has a width larger than that of said two ground strips. 
     
     
       6. An integrated circuit comprising:
 a pad positioned in a ground shield cage, said ground shield cage having a bottom conductive ground element comprising a set of ground strips, at least one ground strip of said set of ground strips being along a signal routing path of said integrated circuit. 
 
     
     
       7. The integrated circuit of  claim 6 , wherein said ground shield cage further comprises:
 a set of stacked conductive ground elements forming sidewalls. 
 
     
     
       8. The integrated circuit of  claim 7 , wherein said sidewalls of said ground shield cage are comprised of at least an inner wall and an outer wall wherein said inner wall is electrically coupled to said outer wall. 
     
     
       9. The integrated circuit of  claim 8 , further comprising a set of vias for electrically coupling each conductive ground element of said set of stacked conductive ground elements to a lower conductive ground element of said set of stacked conductive ground elements. 
     
     
       10. The integrated circuit of  claim 8 , further comprising:
 a conductive element electrically coupled to said pad; 
 at least two tiled layers , positioned below said conductive element; 
 said bottom conductive ground element positioned below said at least two tiled layers; and 
 a conductor routing layer comprising at least one conductor having a conductor routed beneath, and parallel to, a ground strip of said set of ground strips. 
 
     
     
       11. The integrated circuit of  claim 10 , wherein said ground shield cage further comprises:
 a second ground element below a top ground element and a third ground element below said second ground element, said second and third ground elements being positioned respectively parallel to a corresponding tiled layer of said at least two tiled layers. 
 
     
     
       12. The integrated circuit of  claim 11 , wherein said set of stacked conductive ground elements further comprises:
 a fifth ground element, positioned parallel to said at least one conductor running along said signal routing path. 
 
     
     
       13. The integrated circuit of  claim 7 , wherein each sidewall of said sidewalls of said ground shield cage is comprised of a single wall.